Reagan was a Christian but NOT an evangelical. He did not attend church regularly for most of his life.
Unless you use the word evangelical to describe any Protestant who identifies themselves as "Christian".
He did attend Church throughout his life (I think) . . . not as much in Washington because it is such a to do for a President to go to church. Disrupts the congregation. He wrote and spoke a lot about it; he certainly didn’t hide that he was a Christian.
I don’t even know what the label evangelical really means. Every Christian is told in the Bible to evangelize. So every Christian is evangelical. Every Christian is born again (same thing — Christ said we must all be born again when he spoke to Nicodemus). Most people think of themselves as Presbyterian, or Baptist, or Catholic, or Pentacostal . . .
I'm a lifelong Catholic Christian and I see no difference between "mainline" Protestants and so-called "Evangelical"Protestants. They're all just Protestants to me,and I classify Christians by what denomination they are(Baptist,Methodist,Lutheran,etc.),not whether they "evangelize". Harriet Miers is supposedly "evangelical" and she's as secular as you can get.If she counts as "evangelical",anyone is. Jimmy Carter ran as Mr. Born Again and he not only tolerates any form of "Christian",he's buddies with gays,abortionists,and Muslim Jihadists.
If the above people are "Evangelical",I doubt we have to worry about "Evangelicals" reacting to Romney any differently than other protestants, Catholics, and Americans in general.